I use them with the Mosaic Palette + simply because they are nice enclosed storage that has decent rollers for the spools. A bit pricey buying 2 of them as 4 spools for a palette, but it helps maintain the filament so worth it.

Connecting to an N2 Plus??Well other than the guide tube, there is no "hookup"???Get a slightly longer PTFE tube, set the polybox beside the printer on the floor and arch over the guide tube out the top of the polybox to the inlet on the top of the extruder.

So again, yes, in pretty simple terms, it's a box to hold filament. Not ground breaking, but nicely made and they are handy. it actually includes a single long piece of the guide tube that assumed you would cut in half to use with 2 spools, but that tube is basically long enough for a single spool with a polybox on the floor beside an N2 Plus.

The one advantage I can think of using something like a Polybox is that the smaller size means there's less air inside to have to dry out. Otherwise, it's just a lot cheaper to drop your spools in a ziplock w/ a couple packets of DampRid and throw those inside a big plastic bin or bucket.

I just got a PrintDry, turning it on for a few hours a day to keep my active spools dry, feeding the printer out of that.